Not sure of the year of the Beaumont set but aren't the Pontiac for 64?
http://www.kijiji.ca/v-other-auto-parts-and-accessories/barrie/64-69-chevelle-beaumont-pontaic-full-wheel-disc-14/1144199493?enableSearchNavigationFlag=true
Three different wheelcovers shown:
65 Malibu SS / 66 Chevy II Nova SS;
66 Beaumont (based on 64 Pontiac style);
64 Parisienne Custom Sport.
67 Chevelle Malibu Sport Coupe, Oshawa-built 250 PG never disturbed.
In garage, 296 cid inline six & TH350...
Cam, Toronto.
I don't judge a man by how far he's fallen, but by how far back he bounces - Patton